Here’s a shocker: people are more complicated than the caricatures disseminated by their enemies suggest.  Witness the stupefyingly rich David Koch, who together with his brother Charles, presided over a business empire worth some $115 billion. David, who died on Friday at 79 after a long battle with prostate cancer, was at one with his brother in embracing a staunch libertarian philosophy of government and also in his belief in the power of philanthropic investment.